Actinic (solar) keratoses
- Partial thickness dysplasia of epidermal keratinocytes
- A small minority (<1%) of actinic keratoses undergo malignant transformation into squamous cell carcinoma
Clinical features
- Appear as scaly, erythematous papules or patches and feel gritty and rough
- Occur on sun exposed skin especially scalp, face, hands - marker of chronic sun damage
Management
- Lesion-based treatments - cryotherapy, curettage and cautery
- Field based treatments (aimed at clearing visible and subclinical lesions over a larger area) - topical 5-fluorouracil, imiquimod, photodynamic therapy
Bowen’s disease (intraepithelial carcinoma)
- Squamous cell carcinoma in situ - full thickness dysplasia of epidermal keratinocytes
Clinical features
- Typically affects the lower legs in fair-skinned women or the torso in men
- Lesions appear as slowly enlarging, well-demarcated, scaly red patch/plaque with an irregular border
- A variant of Bowen’s disease can affect the genital mucosa - vulval, penile or anal intraepithelial neoplasia
- Strong link with HPV-16 and 18 infection, also more common in immunosuppressed individuals (including HIV)
Management
- Similar to actinic keratosis - cryotherapy, 5-flurouracil cream, imiquimod, photodynamic therapy
Keratoacanthoma